The USS Truxtun, a US Navy guided-missile destroyer, is heading to the Black Sea for what the US military on Thursday described as a "routine" deployment that was scheduled well before the crisis in Ukraine.

The announcement came a day after the Pentagon unveiled plans to put more US fighter jets on a NATO air patrol mission in the Baltics, moving to reassure allies alarmed by Russia's effective seizure of the Ukrainian peninsula of Crimea. (Reuters)